1. Field of the Invention
This invention relates generally to devices used to detect the presence of toxic, explosive or otherwise dangerous gases; temperature; humidity; light; particulate; or other environment parameters, and more particularly to devices used to detect the presence of toxic, explosive, or dangerous gases; temperature; humidity; light; or other environment parameters and permit the operation or actuation of a device when the monitored environmental parameter is in the safe range.
2. Description of the Related Art
Toxic and explosive gas detectors have been used in many different areas. The first gas detector was probably the canary used in mining to indicate toxic atmospheres. Since the use of the canary began there have been many developments in gas detecting technology. Currently gas detectors are used to detect the presence of propane, carbon monoxide, gasoline vapors, hydrogen, oxygen and other gases. Typical sensor or detector locations are: 1) the bilge of a recreational or commercial vessel; 2) the inside of a house; 3) enclosed spaces prior to entry; and 4) areas where dangerous gases may be present due to manufacturing or transportation.
The detectors currently on the market merely provide an indication that a hazard is present or a value of the environmental parameter monitored or measured. This indication may be a warning alarm, a warning light, or meter indication. However, these detectors will not take any other action to prevent an explosion, fire, injury, death, or property damage in the event that an unsafe environment exists. The inability of these detectors to either act in the event an unsafe condition is detected or to permit action only when the environment is safe results in unnecessary injuries, deaths, and damage or destruction of valuable property by fire, explosion, toxic gas, or other environmental hazards.